72,131 research outputs found

    Wess-Zumino Model on Bosonic-Fermionic Noncommutative Superspace

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    In our previous paper we construct a renormalizable Wess-Zumino action on BFNC superspace at the second order approximation of noncommutative parameters. The action contains about 200 terms which are necessary for renormalization. By removing chiral covariant derivatives and chiral coordinates we found that the BFNC Wess-Zumino action can be transformed to a simpler form which have manifest 1/2 supersymmetry. Based on this discovery, we can extend the BFNC Wess-Zumino action to the all order of noncommutative parameters. At first we introduce global symmetries, then obtain divergent operators in the effective action by using dimensional analysis, the next step is to construct all possible BFNC parameters, at the end we combine the BFNC parameters with the divergent operators. We present the explicit action up to the fourth order of noncommutative parameters. Because the action contain all possible divergent operators, it is renormalizable to all order in perturbative theory.Comment: 29 page

    Covariant Quantization of BFNC Super Yang-Mills Theories and Supergauge Invariance

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    To construct renormalizable gauge model in Bosonic-Fermionic noncommutative (BFNC) superspace, we replace the ordinary products of super Yang-Mills model by BFNC star products. To study the renormalization property of the deformed action, we obtain the one-loop 1PI effective action by using background field method at the first order of BFNC parameters. We also verify the BFNC supergauge invariance of the effective action. Because there are new terms in effective action, the deformed action is not renormalizable. This imply that additional terms should be added to the deformed action.Comment: 15 page

    Optimal control for multi-parameter quantum estimation with time-dependent Hamiltonians

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    We investigate simultaneous estimation of multi-parameter quantum estimation with time-dependent Hamiltonians. We analytically obtain the maximal quantum Fisher information matrix for two-parameter in time-dependent three-level systems. The optimal coherent control scheme is proposed to increase the estimation precisions. In a example of a spin-1 particle in a uniformly rotating magnetic field, the optimal coherent Hamiltonians for different parameters can be chosen to be completely same. However, in general, the optimal coherent Hamiltonians for different parameters are incompatibility. In this situation, we suggest a variance method to obtain the optimal coherent Hamiltonian for estimating multiple parameters simultaneously, and obtain the optimal simultaneous estimation precision of two-parameter in a three-level Landau-Zener Hamiltonian.Comment: 9 pages, 1 figure

    CIF: Continuous Integrate-and-Fire for End-to-End Speech Recognition

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    In this paper, we propose a novel soft and monotonic alignment mechanism used for sequence transduction. It is inspired by the integrate-and-fire model in spiking neural networks and employed in the encoder-decoder framework consists of continuous functions, thus being named as: Continuous Integrate-and-Fire (CIF). Applied to the ASR task, CIF not only shows a concise calculation, but also supports online recognition and acoustic boundary positioning, thus suitable for various ASR scenarios. Several support strategies are also proposed to alleviate the unique problems of CIF-based model. With the joint action of these methods, the CIF-based model shows competitive performance. Notably, it achieves a word error rate (WER) of 2.86% on the test-clean of Librispeech and creates new state-of-the-art result on Mandarin telephone ASR benchmark.Comment: To appear at ICASSP 202

    Gradient estimates for divergence form elliptic systems arising from composite material

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    In this paper, we show that W1,pW^{1,p} (1≤p<∞)(1\leq p<\infty) weak solutions to divergence form elliptic systems are Lipschitz and piecewise C1C^{1} provided that the leading coefficients and data are of piecewise Dini mean oscillation, the lower order coefficients are bounded, and interfacial boundaries are C1,DiniC^{1,\text{Dini}}. This extends a result of Li and Nirenberg (\textit{Comm. Pure Appl. Math.} \textbf{56} (2003), 892-925). Moreover, under a stronger assumption on the piecewise L1L^{1}-mean oscillation of the leading coefficients, we derive a global weak type-(1,1) estimate with respect to A1A_{1} Muckenhoupt weights for the elliptic systems without lower order terms.Comment: 34 pages, submitte

    Multi-parameter Quantum Magnetometry with Spin States in coarsened measurement reference

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    We investigate the simultaneous estimation of the intensity and the orientation of a magnetic field by the multi-parameter quantum Fisher information matrix. A general expression is achieved for the simultaneous estimation precision of the intensity and the orientation, which is better than the independent estimation precision for the given number of spin states. Moreover, we consider an imperfect measurement device, coarsened measurement reference. For the case of the measurement reference rotating around the y−y-axis randomly, the simultaneous estimation always performs better than the independent estimation. For all other cases, the simultaneous estimation precision will not perform better than the independent estimation when the coarsened degree is larger than a certain value.Comment: 7pages,3 figure

    Conformal Nets Associated with Lattices and Their Orbifolds

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    In this paper we study representations of conformal nets associated with positive definite even lattices and their orbifolds with respect to isometries of the lattices. Using previous general results on orbifolds, we give a list of all irreducible representations of the orbifolds, which generate a unitary modular tensor category.Comment: 25 page

    Gradient estimates for divergence form parabolic systems

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    We consider divergence form, second-order strongly parabolic systems in a cylindrical domain with a finite number of subdomains under the assumption that the interfacial boundaries are C1,DiniC^{1,\text{Dini}} and Cγ0C^{\gamma_{0}} in the spatial variables and the time variable, respectively. Gradient estimates and piecewise C1/2,1C^{1/2,1}-regularity are established when the leading coefficients and data are assumed to be of piecewise Dini mean oscillation or piecewise H\"{o}lder continuous. Our results improve the previous results in \cite{ll,fknn} to a large extent. We also prove a global weak type-(1,1)(1,1) estimate with respect to A1A_{1} Muckenhoupt weights for the parabolic systems with leading coefficients which satisfy a stronger assumption. As a byproduct, we give a proof of optimal regularity of weak solutions to parabolic transmission problems with C1,μC^{1,\mu} or C1,DiniC^{1,\text{Dini}} interfaces. This gives an extension of a recent result in \cite{css} to parabolic systems.Comment: 41 pages. Submitte

    Resonant Tidal Excitation of Oscillation Modes in Merging Binary Neutron Stars: Inertial-Gravity Modes

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    In coalescing neutron star (NS) binaries, tidal force can resonantly excite low-frequency (< 500 Hz) oscillation modes in the NS, transferring energy between the orbit and the NS. This resonant tide can induce phase shift in the gravitational waveforms, and potentially provide a new window of studying NS interior using gravitational waves. Previous works have considered tidal excitations of pure g-modes (due to stable stratification of the star) and pure inertial modes (due to Coriolis force), with the rotational effect treated in an approximate manner. However, for realistic NSs, the buoyancy and rotational effects can be comparable, giving rise to mixed inertial-gravity modes. We develop a non-perturbative numerical spectral code to compute the frequencies and tidal coupling coefficients of these modes. We then calculate the phase shift in the gravitational waveform due to each resonance during binary inspiral. We adopt polytropic NS models with a parameterized stratification. We derive relevant scaling relations and survey how the phase shift depends on various properties of the NS. We find that for canonical NSs (with mass M = 1.4M_sun and radius R = 10 km) and modest rotation rates (< 300 Hz), the gravitational wave phase shift due to a resonance is generally less than 0.01 radian. But the phase shift is a strong function of R and M, and can reach a radian or more for low-mass NSs with larger radii (R > 15 km). Significant phase shift can also be produced when the combination of stratification and rotation gives rise to a very low frequency (< 20 Hz in the inertial frame) modified g-mode. We also find that some inertial modes can be strongly affected by stratification, and that the m = 1 r-mode, previously identified to have a small but finite inertial-frame frequency based on the Cowling approximation, in fact has essentially zero frequency, and therefore cannot be excited.Comment: 18 pages, 11 figures, 4 table

    Disruption of Planetary Orbits Through Evection Resonance with an External Companion: Circumbinary Planets and Multiplanet Systems

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    Planets around binary stars and those in multiplanet systems may experience resonant eccentricity excitation and disruption due to perturbations from a distant stellar companion. This "evection resonance" occurs when the apsidal precession frequency of the planet, driven by the quadrupole associated with the inner binary or the other planets, matches the orbital frequency of the external companion. We develop an analytic theory to study the effects of evection resonance on circumbinary planets and multiplanet systems. We derive the general conditions for effective eccentricity excitation or resonance capture of the planet as the system undergoes long-term evolution. Applying to circumbinary planets, we show that inward planet migration may lead to eccentricity growth due to evection resonance with an external perturber, and planets around shrinking binaries may not survive the resonant eccentricity growth. On the other hand, significant eccentricity excitation in multiplanet systems occurs in limited parameter space of planet and binary semimajor axes, and requires the planetary migration to be sufficiently slow.Comment: 15 pages, 16 figure
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